1. Field of the Disclosure
The present disclosure relates to an electrophoretic display (EPD) device, and more particularly, to a flexible display which can be manufactured at lower temperatures with a simple structure for colorfully displaying an image.
2. Discussion of the Related Art
Displays are commonly used as a visual information transfer medium as society has become more information-dependent. Displays are being manufactured to have lower power consumption, and be thinner, lighter and have a higher picture quality.
Displays may be classified as an emission type display, in which the display itself emits light and a non-emission type display, in which the display itself does not emit light. Examples of an emission type display may be a cathode ray tube (CRT) such as a Braun tube, an electroluminescent (EL) device, a vacuum fluorescent display, and a plasma display panel. An example of a non-emission type display may be a liquid crystal display (LCD).
A flexible display, which can be folded or rolled without any damage, may become common in display fields. Flexible displays may offer a benefit of being more reliable and less likely to break. Although there are currently various obstacles in realizing a fully-functional and cost-effective flexible display, it may be possible to apply the technique of creating a flexible display to thin film transistor (TFT) LCDs, organic light emitting diodes (OLEDs), and EPDs, as the technique becomes more advanced. The flexible display technique may be difficult to apply to the above-mentioned displays which have a complex structure.
A flexible display may also be referred to as a “rollable display” or “foldable display”. Such a flexible display is formed on or implemented on a thin substrate made of a material that it is not damaged even when being folded or rolled, such as a plastic or paper. A flexible display may be suited to organic EL devices and LCD devices which have a thickness of approximately 1 mm or less.
Organic EL devices exhibit good visibility in dark areas or in areas where external light is incident because organic EL devices emit light. Organic EL devices also have a relatively fast response time making it a good display of moving images. An organic EL device may also be manufactured with a slimness or thin profile used for various mobile devices such as mobile phones because it can be designed to have a thin structure.
In order to implement a flexible display using such an organic EL device, a flexible substrate is made of a material that is flexible, such as plastic. However, flexible displays according to the related art have several problems. An organic EL device manufactured using a flexible substrate such as a plastic substrate is limited in application of the plastic substrate because of a high-temperature process required for manufacture of the organic EL device. Plastic substrates have a melting point lower than that of a glass substrate. Accordingly, a plastic substrate may melt in the manufacture of the display device. Also, the manufacturing process becomes complex because of a larger number of patterns used for driving of the organic EL device.
Recently, a new method capable of applying the plastic substrate to the high-temperature process has been proposed wherein the high-temperature process is carried out under the condition in which a glass substrate is attached to the plastic substrate, and the glass substrate is then detached from the plastic substrate. In this method, however, the process for attaching the glass substrate to the plastic substrate is complex. It is also necessary to perform a plurality of lamination processes. Accordingly, there are drawbacks of possibility of defects and a degradation in productivity.